Electric tester



April 11, ma

A. L. sMm-l ELECTRIC TESTER Filed June 2a. 192e 'for use with interna-l Patented Apr. 17, 192s.

UNITED STATES ARTHUR L. SMITH, OF PORTLAND, OREGON;

ELECTRIC TESTER.

Application led .Tune 28, v1926. Serial No. 119,072. T

My invention relates to electric testers in general, and particularly to such devices'as are used for testing and regulating the fuel fed to furnaces of various sorts, boilers, internal combustion motors, and the like, the device being substantially the same work as the well known CO2 machine commonly used for analyzing the products of combustion, the object being to provide a device without chemicals, liquids or containers therefor, and without moving parts or parts subject to wear, that willanalyze the products of combustion and visibly display the results thereof before theoperator, showing at all times whether the fuel is too rich in hydrocarbons or too lean therein, or normal.

Although my device may be adapted for any sort of fuel, it is partlcularly designed for use with liquid fuels, and also while it may be adapted for boilers, furnaces, kilns, retorts, bake ovens, or anyl location where fuel is consumed, it is particularly adapted combustion motors and is so illustrated and described herein.

I accomplish the above objects by means of the construction illustrated in the accompanying drawing,`which is a part of this application for Letters Patent, and which is a diagrammatic view of my device.

. device is shown In the drawing the analyzing unit of my pipe l oflan internal-combustion motor.

In general my device consists of an analyzing unit mountable within the path of the products of combustion from the motor, a recording unit mountable within convenient view of the operator, and such operating means connecting said units as will sults obtained at the former, and connected with said operating means a device operated by said means to operate the fuel supply valve. e

ThereA are several analyzing units that may be-usedfor this purpose, such as heat units, chemical units, and the like. I have discovered, however, that anelectro-chemical analyzing unit is preferable for this service, and have accordingl invented and developed into'commercia form such an analyzing unit, one convenient form thereof being illustrated in the accompanying drawing. This unit may be mounted in any convenient mounted upon the exhaust vthe exhaust manifold, the exhaust pipe, or

any such position. I have found, however, that the intense heat as Well as the violence of combustion within the motor cylinder is not l,conducive to delicate action of the analyzing unit, and also in that position such unit will analyze the products of combustion within that particular cylinder only. If mounted within the exhaust manifold, or the exhaust pipe as illustrated in the drawing, the analyzing unit will be removed from the intense heat and violent combustion within the motor cylinder, and will also be acted upon by the combined products of combustion fromall the motor cylinders.

Certain metallic oxides are very good electrical insulators, and I have found that such oxides are readily formed upon metals introduced into the hot fuel mixture rich in oxygen and lean in. hydrocarbons, and are as readily again reduced to metallic form when introduced into a hot fuelmixture lean in oxygen and rich in hydrocarbons. The same results are obtained from hot productsof combustion as from hot fuel mixtures, and since all fuel mixtures are not heated, and all products of'combustion are, and since a certain amount of heat is necessary for prompt action of the analyzing unit, I prefer to mount such unit within the path of the products of combustion as illustrated in the drawing.

If a pair of metallic members, such as copper or the like, Vbe mounted in 'contact one with the other in the path of the products Aof combustion from an internal com- .bastion motor, an oxide of such metal will be formed upon the surfaces of such members, and will extend to the surfaces thereof in contact, ifsuch products of combustion are over rich in oxygen and lean in hydrocarbons, the over supply of hot oxygen being the oxidizing agent. On the other hand, if the product-s of combustion are lean in oxygen and rich in hydrocarbons, the excess of hot carbon will attack such oxide as has been previously formed and reduce the same to metallic form. If, however, the fuel mixture has been proper for themotor, containiris f hydrocarbon (fuel), then thepro ucts of rent of the resi-stance or lack of resistance caused by the presence or absenceV of such oxide -between said metallic members.

I have illustrated in the drawing a coinveni'ent form of the analyzing unit, wherein I show a casing 2 adapted for lnsertlon 1n the exhaust pipe/1, and having a' cap 3 se- 'Y core a short distance. aremountedupon capA 3 and the a normal. amount of copperl oxide to form on cording instrument, and cause the `said core being preferably of cured thereupon. Mounted in cap 3 is' an in- 5 thereupon, orcelain. A'

sulating core 4 with a shoulder stem 6 is passed through said core, and mounted in an insulating bushing 7 in the casing 2. A Integral with said stem -is a cupped. washer 8 embracing theend `of the Acore 4 with clearance for said'stem and said washer 't0 move longitudinall 'upon said the core 4 between the 'washer 8, and these metallic washers are slightly clamped between, said `cap, and said washer 8 by means of a spring 10 upon the stem 6.

A source of V11 is provided, as well as the recording 1nstrument 12, which latter may be either an ammeter or a voltmeter. The electric current circuit is from the .battery 11 through Vwire 13 to the recording instrument 12, wire 14, double pole switch 15,wire'16, stem'6, washer 8, metallic washers 9, cap 3, and wire 17 to the battery.

. Let it be supposed that the device is started on a motor with a predetermined correct fuel mixture, andwith the disks inv contact one with the other. Also that the recording instrument 12 is so adjusted that after the motor has been running afsuliicient time for the disks' 9 the pointer of said .recording instrument stands at the pointmarked N representing a normal mixture of the fuel, and l also that the fuel mixture isright for the motor. stances, the fuel mixture becomes too lean, and thus contains too great a percentage of oxygen, this hot oxygen in passing the analyzlngl unit will oxidize the .metallic disks or was ers9, and there will thus be depositi ed between the adjacent washers a thin lm -of metallic oxide. Thisvxne'tallc oxide being an 'insulator will thus nsert'resistance into the electric circuit, and thus aiect the reointer 'rd the left, indlcating thereof to move tow 5 that the fuel mixture is too lean, whereupon neither excess of air (oxygen or of.

be passed through 'instrument any change in thev that-may occur for any reason,

Metalllc washers 9 electric current, as the batteryv function Y .when caused by. If then, through any'` c1rcum is thrown to ope 1,eee,27a

thevoperator may o en the needle valve of the carburetor and t us enrich the fuel mixe ture.

.Should the fuel mixture` thereafter be- Colne too rich, and thus cont-ain too great a ercentage of carbon, this hot carbon passlng the analyzing unit will reduce the oxide .between the metallic washers to metallic the fuel mixture is too rich. Whereupon the operatorvmay close the needle valve of the carburetor and thus lean the Xfuel mixture. As long as the fuel mixture remains proper for the motor the hand of the recording instrument will remain fixed at VN or normal. v

The operation of the analyzing unit is continuous, registering upon the recording fuel mixture the products of combustion being constantly'analyzed by the electro-chemical action of the analyzing unit, andthe results registered on. the recording'instrument.

As so far explained the device simply analyzes .the products ofk combustion and records the results upon a recording instrument, butgit is desirable thatthe .device be .enabled to operate the carburetorindependj ently of the operator and thus render the adjustment of the carburetor an' automatic of the analyzing unit, andthis I accomplish as follows. e

Within the hub 20 of the carburetor 21 I mount a slidable sleeve 22 within which the needle valve is threaded. I vconnect said sleeve 22 -with said hub 20 by means of a air of toggle Iarms 24, one of said arms eing secured to said sleevel and the other arm to said hub. Mounted adjacent the carburetor, convemently upon abracket 25 se? cured thereto, 1s a solenoid 26 having a. core 27 with an annular groove 28 therein.v Said core rides upon a rod 29 which is mounted upon suitable 'brackets 30 at each end of the solenoid..and. sprin 31 are provided to retain the core 27 '1n its central position normally, butto Aallow movement thereof the solenoid. Thimbles 32 are threaded into said bracket 30 for the purpose of adjusting the tension of vthe springs 31'. vA. lever 34 is ivoted upon a bracket 35, one end thereo being a apted to engage 'the groove 28 in the core 27. The opposite end of said lever is connected to the common pivotalv point of said toggle arms 24 by a rod 36.

Let it now be supposed that the switch 15 n the circuit .previously described, and to close the circult through the solenoid, Thenthe current passes from the battery 11 through wire 13, recording lll -instrument'12, wire l134, switch 15, wire-40,

' solenoid 26, wire 41, wire 16, stem 6,- metallic washers ,9, cap 3, wire 17, to lthebattery. AThus any variation in the electric current caused by variatlon in the fuel mixture will .not only be recorded upon the recording instrument, but will alsoenergize the solenoid 426 and'thus cause. movement of the lever- 34 `and operation of the toggle 24 to `open or Thus the fuel.'

ment of parts found desirable in materializautomaticallv adjusted to 'ing my invention, I wish to include in this apbplication all mechanical equivalents and su stitutes that may fairly be considered to v come within the scope and purview of my invention as defined in the appended claims. Having disclosed my invention so that others may be enabled to construct and to use the'same -what I claim as new and desire to secure lby Letters Patent is.:

1. In an electrical tester: an electro-chemical analyzing unitmountable in the path of for a device of this charf said analyzing 'at Portland, countyof Multnomah',-

the products of combutionfrom a fuel burnlng device; an electrical recording instrument; and an electric circuit connecting said analyzing unit and said instrument.

2. vMetallic contacting members mountable inthe path of the productsof combustion of burning fuel; an' electrical recording in- Jstrument; :and an electric circuit including said metallic members, ment, and a source of electric ener 3. In an electric tester for liqui fuel: an electro-chemical analyzing unit mountable in the path of the products of combustion; a fuel regulating device; and an 'electromagnetic mechanism controlledb said anal zingunit for controlling saidy el regulating device. i

4. In an electric tester: an electro-chemical analyzing unit mountable in the path of the products of `combustion of a burning fuel; an electromagnet; mechanism to operate the said recording instrul needle valve of a carbuertor from. said elcc tro-magnet; and an electric circuit including unitvand said electro-magnet.

In testimony' whereof I' clai1n`the forego ing as my own I hereunto aix my Aai ature Oregon, this 23rd daof. J une, 1926.

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